1. Field of the Invention
The present invention relates generally to a Mobile IP network, and in particular, to a method for defining a cost function and calculating a cost factor, especially hop count in a Mobile IP network.
2. Description of the Related Art
Recently, Internet Protocol (IP) networks have been rapidly developed owing to the rapid progress of Internet technology. In such an IP network, each user and a particular server operate with a fixed address, or an IP address, and routing is performed based on such address.
Meanwhile, in order to provide more data to mobile nodes (MNs) in a mobile communication system, various technologies have been proposed. As one of such technologies, the so-called Mobile IP technology for assigning an IP address to a MN has been introduced. Regarding the Mobile IP, many discussions are taking place in the Internet Engineering Task Force (IETF) and research is currently being conducted on the Mobile IP version 6 (Mobile IP v6) protocol.
In a Mobile IP system, the definition of a cost function is very important for IP routing. The cost function becomes a very important factor for message routing in a communication system using not only Mobile IP but also general IP. However, in MIP v6, which is currently being actively researched, the cost function, which is a very important factor for determining routing, has not been defined yet. That is, up to now there is no method for correctly transferring desired traffic data to a MN using Mobile IP.